Yoke apparatus for yarn carriers

ABSTRACT

Apparatus for winding spools with textile yarns comprising a yoke of two arms which are secured on a common shaft and which terminate in aligned spool-mounts. The portion of the shaft between the mounting points of the arms acts as an elastic or torsion-bar system to permit the arms and their spool-mounts to yield to accommodate static or dynamic variations in the spool.

United States Patent [191 Loquineau et al.

[ Jan. 21, 1975 YOKE APPARATUS FOR YARN CARRIERS [75] Inventors: Jacques Loquineau,

Commelle-Vernay; Rolland Sartori, Riorges, both of France [73] Assignee: Rhone-Poulenc-Textile, Paris,

France [22] Filed: June 26, 1973 [21] Appl. No.: 373,785

[30] Foreign Application Priority Data June 26, 1972 France; 72.23276 [52] US. Cl '242/18 DD,242/129.5'1 [51] Int. Cl B65h 54/42 [58] Field of Search 242/18 DD, 129.51, 68.4,

[56] References Cited UNITED STATES PATENTS 1,324,889 12/1919 Foster 242/18DD 2,197,747 4/1940 Naumann 242/18'DD 2,231,837 2/1941 Elvin et al 242/18 DD FOREIGN PATENTS O R APPLICATIONS 1,052,831 9/1953 France 242/129.51 1,292,242 3/1962 France 242/18 DD 1,138,335 1/1969 Great Britain 242/18 DD Primary ExaminerStanley A. Gilreath Attorney, Agent, or FirmSherman & Shalloway [57] ABSTRACT Apparatus for winding spools with textile yarns comprising a yoke of two arms which are secured on a common shaft and which terminate in aligned spoolmounts. The portion of the shaft between the mounting points of the arms acts as an elastic or torsion-bar system to permit the arms and their spool-mounts to yield to accommodate static or dynamic variations in the spool.

- 10.Claims, 3 Drawing Figures PATENTEDJANZI 197s Z ,rlu. F

YOKE APPARATUS FOR YARN CARRIERS BACKGROUND OF THE INVENTION The present invention relates to the winding of textile yarns on yarn carriers and is concerned, more particularly, with the mounting of yarn-carriers on pivoting yokes to accommodate variations in static dimensions or dynamic behavior of such carriers so that they may be wound at speeds up to and including the extremely high winding-speeds now encountered.

BRIEF DESCRIPTION OF THE PRIOR ART Textile yarn-winding yokes typically comprise a pair of solid arms which are spaced from and parallel with each other. Each carries, at one of its ends, a flange for gripping the carrier or spool. The periphery of the spool bears against a driving roll which imparts the winding force to the spool. The yoke pivots on an axis passing directly through the ends of the arms remote from the ends carrying the flanges and spool. The textile yarn is distributed along the spool in a reciprocating motion by a yarn-guide which assures a positive traverse of the winding.

At relatively low winding speeds, such as speeds below 500 meters per minute, such rigid yokes operate quite satisfactorily. The yoke disclosed in co-pending U.S. Ser. No. 287,080, which was filed Sept. 7, 1972,

by Rolland Sartori, has been found to be particularly advantageous. This yoke mounts the yarn-carriers most securely by the use of gripping flanges which engage the ends of the yarn-carrier.

The carrier-mounting yoke of that invention provides for a gradually yielding pressure on the yarn-carrier to accommodate the increasing diameter and weight of the winding. At the same time, a constant contact is assured between the periphery of the winding and the surface of the drive rollers so that bouncing or rebounding are not a problem at such low speeds.

However, when the winding speeds are increased, difficulties in the use of rigid yokes are encountered. For the higher speeds, of the order of 2,000 m/min or more, it becomes impractical to use prior yokes with the common cardboard or plastic spools.

Actually, such carriers or spools have rather broad fabrication tolerances, as they are currently supplied by manufacturers. They are not perfectly balanced and their dimensions are not absolutely uniform. Therefore, at high speeds, the bouncing or rebounding effect resulting from the geometric defects or dynamic variations develops into continuous hammering. At critical speeds, (where the fundamental or natural frequencies are approached) this generates substantial vibrations which requires shutdown of the winding system.

These vibrations are further amplified by the fact that a considerable force is applied against the spool to maintain the required contact against the drive roller. With this force counteracting the rebound tendency of the spool, the spool is subjected to stresses which it transfers to the bearings via the flanges and, as a result of the deflection or cocking of the stub-shafts in the bearings, the ends of the spools are worked or continuously distorted on each rotation.

The material forming the spool, as it is continuously worked or flexed during rotation, experiences deterioration or structural breakdown in the regions in which the spool is engaged by the two flanges. This deterioration further aggravates the general imbalance of the system and the severity of the vibration or hammering upon reaching critical speeds. This phenomena is sufficient to cause rupture of the spool, if the winding operation is not stopped or the speed reduced to safe levels.

Attempts have been made at solving these problems by the use of rugged metal spools having precise geometrical and mechanical specifications, instead of the ordinary cardboard or plastic spools. Although these spools have been adequate with regard to the foregoing technical problems, they have not proven to be economically feasible or profitable, particularly because of their high cost.

OBJECTS OF THE INVENTION Therefore, it is an object of the present invention to provide a yarn-carrier mount which can safely wind common yarn-carriers at winding speeds in excess of 2,000 m/min.

A further object of the invention is the provision of a yarn-carrier mount which can accommodate geometrically and dynamically imperfect yarn-carriers.

Another object of the invention is the provision of a yarn-carrier yoke whose arms are elastically positioned to accommodate, individually, imperfections at different locations along the yarn-carrier.

A still further object of the invention is the provision of a yarn-carrier yoke which mounts the carrier by means of flanges engaging the carrier-ends and which can safely wind the yarn-carriers at speeds in excess of 2,000 m/min.

SUMMARY OF THE INVENTION In general, the preferred form of the present invention comprises a biased, pivoting yoke for holding a textile yarn-carrier spool to be driven by its periphery. The yoke includes a pair of arms arranged on parallel planes and each having, adjacent one of its ends, a rotatable flange for gripping the spool at its ends, with the two flanges being coaxial with each other under normal conditions. The yoke further includes joining means for joining the arms in spaced substantially parallel relationship, which joining means includes elastic means flexibly responsive to variations or reactions of the spool while it is being rotated to permit an angular displacement of the two arms relative to each other.

As used herein, the phase reactions of the spool? refers to the stresses that the rotating spool imposes on the flanges as a result of the spools dimensional or dynamic imperfections. Preferably, the relative angular displacement of the arms occurs primarily on individual planes perpendicular to the pivot axis of the yoke. This plane will be referred to hereinafter as the plane of displacement.

The flexing means, by which the yoke is sensitive or responsive to the reactions of the spool, is arranged to permit angular displacement of at least that part of the arm which carries thespool-mounting flanges. The angular displacement preferably is accomplished by means of a flexing of the two arms, which are parallel under nonnal conditions, about a common axis parallel to the pivoting axis of the yoke. Most advantageously, the flex-axis of the arms is arranged to coincide with the pivot axis of the yoke.

Preferably, the flexing means includes an elastic linking system between the two arms and which is deformable at least in the direction which permits the arms to move in the plane of displacement.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the objects and advantages of the invention may be derived from the following description and the accompanying drawings, in which:

FIG. 1 is a generally vertical, sectional view of the preferred form of yieldable yoke of the invention;

FIG. 2 is a sectional view taken along lines IIII of FIG. 1; and

FIG. 3 is a view of a fully wound spool as produced by the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1 and FIG. 2, the preferred form of the present invention includes a drive roller 1, which is driven at a constant speed and against which is pressed the yarn-winding 2 which is wound on a cardboard yarn-carrier or spool 3. The textile yarn, which may be of any size or composition, is fed to the spool 3 in a reciprocating motion on a plane parallel to the axis of the drive roller 1, by a cam 5 which controls a yarn-guide 6.

A pair of generally symmetrical arms 7 and 8 each have one of their ends rigidly secured at spaced points on a shaft 9 by any suitable means such as by clamping or by keys. The arms 7 and 8 are arranged substantially parallel with each other and extend from the shaft 9 on the same radius, so that they form a U-shaped arrangement or yoke.

The shaft 9 is journalled at its ends, thereby forming pivots in bearings 10, 10' which are mounted on a fixed structure such as the frame members 11 and 11,' respectively. At their ends remote from the shaft 9, the arms 7 and 8 carry aligned bearings 12 and 13, respectively, which receive stub shafts l4 and 15, respectively, for both sliding and rotational movement therein.

The stub shafts l4 and have flanges 14' and 15 for engaging and gripping the ends of the spool 3, and are biased, as at F, against the spool (by means not shown). Preferably, the flanges are of the type disclosed in the aforementioned US. application Ser. No. 287,080 filed Sept. 7, 1972, and are biased against the spool as taught in that application.

In its center, the shaft 9 has a lever 16 rigidly secured thereto and extended in a direction generally opposite the radial direction of the arms 7 and 8. As best shown in FIG. 2, the lever 16 engages a cable 17 which passes over a pulley 18 to a conventional counterweight assembly 19. Although it is not necessary that the cable 17 be formed of elastic material, elastic material is preferred in order to prevent the counterweight 19 from going into a resonant motion.

The counterweight 19 acts through the shaft 9 and the arms 7, 8 to cause the spool 3 to be pressed or biased against the drive roller 1. The amount of this bias can be regulated by changing the number of the individual weights making up the counterweight assembly 19.

The profile or shape of the shaft 9 is modified, in accordance with empirical study, to form two tapering, reduced-portions 9a and 9b, on opposite sides of the lever 16. The shaft portions 9a and 9b then form two torsion-bars which are symmetrical with regard to the intermediate lever 16, against which the counterweight l9 acts. The shaft section 9a thus acts as a torsion bar between the arm 7 and the lever 16 and the arm 8, while the shaft section 9b acts for the arm 8 to complete the flexing portion of the yoke.

Therefore, each of the arms 7 and 8 is capable of angular displacement with regard to the other, each along its own plane of displacement. Consequently, each is capable of independent response to the reactions of the rotating spool.

Preferably, each of the arms 7 and 8 is engaged, at its outer end, by a damper or shock-absorber such as the shock-absorber 21 shown engaging the outer end 20 of the arm 7 (FIG. 2).

While the torsion bars and 9b have been shown in their preferred, symmetrical form, it is to be understood that dimensional symmetry is not absolutely necessary. Similar results may be achieved with bars of unequal lengths and shapes.

Also, although the use of the gripping flanges is preferred, other spool mounts may be substituted on the arms.

EXAMPLE Windings, such as shown in FIG. 3, were made on a winding installation equipped with a yoke having the flexing means disclosed in FIGS. 1 and 2, at a winding speed of 3,000 m/min.

The textile yarn was a polyester I67 d tex/30 strand, and was wound on rolled-paper spools of the dimensionsz L=420 mm ID=68 mm OD=7S mm The spools initially exhibited a false-round or eccentricity of 0.3 mm. In spite of the imperfections, it was possible to make biconical windings with an angle alpha" of 20 with respect to a perpendicular to the axis of the spool. The length A" of the winding, at its base. was 370 mm and its diameter D was mm. The several windings weighed between 6 and 7 kg and exhibited no false-rounds or surface irregularities.

It is significant that, with a prior art, rigid yoke, it would have been impossible to wind at this 3,000 m/min speed with a tube of this type. In order to achieve the same winding, with gripping of the carrier spool by its ends, it would have been necessary to reduce the winding speed to below 1,000 m/min.

The example clearly shows the advantages of the invention in making it possible to achieve textile yarnwindings at winding speeds of 2,000 m/min and more, even when using yarn-carrier tubes or spools made of cardboard or any other inexpensive material, such as plastics, composites, thin metals and the like, regardless of the fact that they are fabricated to the usual manufacturing tolerances.

It is to be understood that various, alternate forms of flexing means may be employed instead of the symmetrical torsion-bar system shown, as long as the required elasticity is present.

The important feature of any such system is that both arms biased to press the spool against the drive roller and that the biasing means includes an elastic member to permit either or both arms to be flexed or displaced to accommodate imperfections in the yarn-carrier.

It is further to be understood that, although the greatest advantages of the invention are realized when windings are made at high speeds of 2,000 m/min or more, the yoke of the invention is also of distinct advantage in operations in which windings are made at lower speeds.

Various changes may be made in the details of the invention, as described, without sacrificing the advantages thereof or departing from the scope of the appended claims.

We claim:

1. Apparatus for mounting a yarn carrier for winding a textile yarn thereon said yarn carrier being driven by a peripheral drive, including a pair of arms,

means for joining said arms in spaced substantially parallel relationship,

a pivot at one end of each arm, said pivots being coaxially aligned with each other, said arms each havmg yarn-carrier mounting means aligned with each other remote on said arms from said pivots,

bias means for biasing said arms toward the peripheral drive,

and flexing means including an elastic linkage in said joining means for permitting angular displacement of said arms with respect to each other.

2. Apparatus according to claim 1 in which said joining means includes an axle aligned with said pivots.

3. Apparatus according to claim 2 in which said biasing means includes a member engaging said axle.

4. Apparatus according to claim 3 in which said flexing means includes an elastic portion in said axle intermediate said pivots.

5. Apparatus according to claim 4 in which said axle is formed of a unitary piece of material.

6. Apparatus according to claim 5 in which said elastic portion includes a reduced-dimension zone of said axle intermediate the pivots.

7. Apparatus according to claim 6 in which said axle includes two reduced-dimension zones and said biasing member engages said axle intermediate said reduceddimension zones.

8. Apparatus according to claim 7 in which said biasing member engages said axle at a point midway between said pivots, and said reduced portions comprise tapered portions.

9. Apparatus according to claim 2 in which each end of said axle forms one of said pivots, respectively.

10. Apparatus according to claim 7 in which each end of said axle forms one of said pivots, respectively. 

1. Apparatus for mounting a yarn carrier for winding a textile yarn thereon said yarn carrier being driven by a peripheral drive, including a pair of arms, means for joining said arms in spaced substantially parallel relationship, a pivot at one end of each arm, said pivots being coaxially aligned with each other, said arms each having yarn-carrier mounting means aligned with each other remote on said arms from said pivots, bias means for biasing said arms toward the peripheral drive, and flexing means including an elastic linkage in said joining means for permitting angular displacement of said arms with respect to each other.
 2. Apparatus according to claim 1 in which said joining means includes an axle aligned with said pivots.
 3. Apparatus according to claim 2 in which said biasing means includes a member engaging said axle.
 4. Apparatus according to claim 3 in which said flexing means includes an elastic portion in said axle intermediate said pivots.
 5. Apparatus according to claim 4 in which said axle is formed of a unitary piece of material.
 6. Apparatus according to claim 5 in which said elastic portion includes a reduced-dimension zone of said axle intermediate the pivots.
 7. Apparatus according to claim 6 in which said axle includes two reduced-dimension zones and said biasing member engages said axle intermediate said reduced-dimension zones.
 8. Apparatus according to claim 7 in which said biasing member engages said axle at a point Midway between said pivots, and said reduced portions comprise tapered portions.
 9. Apparatus according to claim 2 in which each end of said axle forms one of said pivots, respectively.
 10. Apparatus according to claim 7 in which each end of said axle forms one of said pivots, respectively. 